How are people controlling customer supplied CAD files in their systems, especially when a blueprint is never issued? Are you attempting to make blueprints from the CAD file? What do you do with PPAP when the customer requires you to sent a print with the submission and all you have is the CAD file?
Is there any activity by AIAG or other groups to standardize how these systems should work?

The problem is that we don't have the software to open it up. We are given the CAD files, and really haven no means of using them internally. We are attempting to have our pattern builders print them for us, but they really don't have the time or resources.

Control it (them) as a controlled data file. As with all electronic data it must be backed up.

Make printouts only to work from when necessary.

Contact your customer's supplier QA activity and ask if they want a copy of the data file or a printout (the assumption is if you have the data file you have the software to open the file).

I know of no 'standard' control system other than the 'typical' control mechanisms - just like document control: Master list, etc.

Don't over complicate the issue in your mind.